Propeller



-May 12, 1942. H. J. JOHNSON PROPELLER Filed Dec. 12, 1959 2Sheets-Sheet 1 12277 ffindon,

B @Mwxir Attorneys May 12, 1942. H. J. JOHNSON PRQPELLER Filed Dec. 12,1939 2 Sheets-Sheet 2 Inventor Attorneys Patented May 12, 1942 UNITEDSTATES PATENT OFFICE PROPELLER.

Harry J. Johnson, Alma, Colo.

Application December 12, 1939, Serial No. 308,853

2 Claims.

The present invention relates to new and useful improvements inpropellers of the screw type particularly for aircraft and has for itsprimary object to provide, in a manner as hereinafter set forth, adevice of this character embodying a novel construction and arrangementwhereby the usual air pressure or resistance at the central or hubportion will be substantially eliminated and at the same time materiallyincrease the atmospheric pressure or density at the outer portions ofthe blades in the region of the greatest load on said blades.

Other objects of the invention are to provide a propeller of theaforementioned character which will be comparatively simple inconstruction. strong, durable, highly efficient and reliable in use,light in weight and which may be manufactured at low cost.

All of the foregoing and still further objects and advantages of theinvention will become apparent from astudy of the followingspecification, taken in connection with the accompanying drawingswherein like characters of reference designate-corresponding partsthroughout the several views, and wherein:

Figure 1 is a view in front elevation of a propeller constructed inaccordance with the present invention.

Figure 2 is a view in side elevation thereof.

Figure 3 is a rear elevational View.

Figure 4 is a view of the blank from which the front of the propeller isformed.

Figure 5 is a view of the blank from which the rear of the propeller isformed.

Figure 6 is a sectional view, taken substantially on the line 66 ofFigure 1.

Figure 7 is a sectional view, taken substantially on the line 1-1 ofFigure 1. v

Figure 8 is a detail view of one of the side plates.

Referring now to the drawings in detail, it will be seen that theembodiment of the invention which has been illustrated comprises frontand suction faces of the blades and the back or rear plate 2 thepressure faces of the blades. The leading edge of each blade is shown ata and the trailing edge at b.

Extending from the hub portion 3 into the The plates l and 2 are 1 innerportions of the blades 4 on the leading edges a of said blades areplates 6. The plates 8, in conjunction with the front plate I of thepropeller, define elongated air intake openings I in the forward edges 0of the blades. trated to advantage in Figures 2 and 6 of the drawings.Curved deflectors 8 are provided for directing the air which enters fromthe atmosphere through the openings I toward the outer ends of thehollow blades 4. The deflectors 8 are of a construction and arrangementto accomplish this with a minimum of turmoil and resistance, saiddeflectors extending from the comparatively wide inner ends of theopenings 1 in the hub structure 3 to the trailing edges b of the 1blades 4.

Referring now to Figures 3, 5 and-7 of the drawings, it will be observedthat the outer rear portions of the back plate 2 of the blades 4 are cutaway, as at 9, in a manner to provide air outlet openings H) from saidblades to the atmosphere. Mounted in the outer portions of the blades 4is a plurality of deflectors II which are arranged to uniformlydistribute the outgoing air as it passes through the discharge openingsIII to the atmosphere. As will be seen these deflectors II are spaceddifferent distances apart with the inner ones placed closer togetherthan the outer ones which causes the air to be equally distributedthrough the opening 10 and, of course, these deflectors change thecourse of the air and they prevent the air from passing freely throughthe space l0 so that this air will build up atmospheric pressure ordensity at the rear of the blades and at the outer portions thereof.

It is thought that the manner in which the propeller functions will bereadily apparent from a consideration of the foregoing. The constructionand arrangement is such as to substantially eliminate the building up ofair pressure or resistance at the central or hub portion of thepropeller. Instead of this occurring as with propellers in widespreaduse at present the air in front of the central or hub portion of thepropeller is drawn into the inlet openings 1 and thrown by centrifugalforce through the hollow blades 4 to the outer ends thereof from whichit is discharged to the atmosphere through the openings l 0 in a mannerto build up atmospheric pressure or density immediately to the suctionfaces of the blades and at the outer end portions thereof in the area ofthe greatest load. Thus, the efficiency of the propeller is greatlyincreased.

It is believed that the many advantages of a propeller constructed inaccordance with the This is illuspresent invention will be readilyunderstood and although a preferred embodiment of the device is asillustrated and described, it is toberunderstood that changes in thedetails of construction and in the combination and arrangement of partsmay be resorted to which will fall within the scope of the invention asclaimed.

What is claimed is:

1. A propeller of the class described comprising a hollow hub and hollowblades radiating from said hub, the front edge of each blade having anopening therein which extends from the central portion of the front edgeof the hub to a point at the front edge of each blade an appreciabledistance from the hub, a pair of deflector plates in the propeller inrear of each opening and each plate extending from a point at the centerof the front and side edge of the hub to the trailing edge of a bladeand each plate curving rearwardly and outwardly and deflecting the airentering an opening to the outer end of a blade, the outer end of eachblade having an opening therein which passes through the trailing edgeand through the.pressure face of the blade, the front wall of theopening, in the pressure face of the blade, curving from the trailingedge forwardly and outwardly to the outer end of the blade, alongitudinal row of spaced deflector plates having their rear endsextending into the last-mentioned opening and said ends beingsubstantially at right angles to the length of the blade with theforward ends of these plates located between the suction and pressurefaces of the blade and slightly curving toward the hub and said platesacting to deflect air passing through each blade toward the trailingedge of the blade said plates being unequally spaced apart with theplates at the irmer end of the row placed closer together than the otherplates.

2. A propeller of the class described comprising a hollow hub and hollowblades radiating from said hub, the front edge ofeach blade having anopening therein which extends from the central portion of the front edgeof the hub to a point at the front edge of each blade an appreciabledistance from the hub, deflector means in the propeller in rear of eachopening for deflecting the air entering an opening to the outer end of ablade, the outer end of each blade having an opening therein whichpasses through the trailing edge and through the pressure face of theblade, the front wall of the last mentioned opening, in the pressureface of the blade, curving from the trailing edge forwardly andoutwardly to the outer end of the blade, a longitudinal row of spaceddeflector plates having their rear ends extending into thelast-mentioned opening and said ends being substantially at right anglesto the length of the blade with the forward ends of these plates locatedbetween the suction and pressure faces ofthe blade and curving towardthe hub and said plates acting to deflect air passing through each bladetoward the trailing edge HARRY J. JOHNSON.

